Answer:
Number added: 42.25 or 4169
Step-by-step explanation:
Put in the other dudes answer and it was wwrong
To make complete square, [tex]\frac{169}{4}[/tex] is to be added.
If any quadratic equation like [tex]x^{2} +bx+c=0[/tex] is given.
To making complete square , add and subtract [tex](\frac{b}{2} )^{2}[/tex]
Given function is,
[tex]x^{2} +13x+15=0[/tex]
After comparing, We get [tex]b=13[/tex]
Thus, to make complete square, We have to add
[tex]=(\frac{13}{2} )^{2}=\frac{169}{4}[/tex]
Learn more about the quadratic function here:
https://brainly.com/question/25841119
